The present invention relates to an apparatus for retrieving character strings, and particularly to an apparatus for retrieving or finding out necessary and/or significant character strings or messages from a group of sentences, data and text.
Character string retrieval apparatuses have important roles in achieving word-processing and inter-translation of languages, searching key words included in records of a data base, and performing pattern recognition in video data processing.
Conventional data retrieval processing has been performed by software in computers, and in such cases, a character string input is sequentially compared to all the standard character strings registered. Accordingly, if there is an error in inputting character strings such as omission of some characters in the input character strings or input of unnecessary characters, then satisfactory search or retrieval cannot be expected. If the system is designed to avoid the effect of such errors in the input data, then the number of the registered standard character strings becomes too large, resulting in too lengthy a processing time.
As described above, the conventional technique for retrieving or searching character strings by computers has bee disadvantageous in that the processing time of character strings is too slow and in that flexibility in treating errors included in input character strings is poor.